<!DOCTYPE HTML>
<html lang="zh-CN">
<head>
    <meta charset="UTF-8">
    <title>ydw</title>
    <link href="css/header.css" rel="stylesheet">
    <script src="js/hello.js"></script>
</head>
<body>
<div id="header">
    The header
</div>

<div id="container">
    <div id="button">
        <button type="button" onclick="hello()">Click button!</button>
    </div>
</div>

<div id="footer">
    <div>
    </div>
</div>
</body>
</html>